Landfill mining project yields positive results in Spain

Construction and demolition landfill. (Reference image by MPCA Photos, Flickr.)

An illegal hillside dumping ground for construction and demolition waste in Andalusia, Spain, has been reverted to its natural state through landfill mining.

According to a paper in the International Journal of Environmental Engineering, almost 90% of the waste materials sitting at the site near the town of Dehesas Viejas were retrieved and found to be low-hazard and suitable for road construction projects or backfilling conventional landfill sites that have been mined.

In a media statement, the paper’s lead author David Caro Moreno said that landfill mining is an emerging approach for the remediation of old waste sites. It allows for the reuse of valuable materials, such as plastics and metals that may have been dumped before recycling facilities were widely available. The process might also allow an entire brownfield site to be remediated sufficiently for development or even rewilding.

For Caro Moreno and his co-authors, in places where mining of conventional, municipal landfill might be required, there is perhaps a greater need for segregation of the waste materials during the recovery process so that they can be reused or recycled. Their research, nevertheless, bodes well for clearing up other big fly-tipping or illegal landfill sites.

“Landfill mining could become an effective approach to addressing the environmental hazards posed by old landfill sites. Moreover, it could offer a supply of raw materials, such as rare and difficult-to-source metals used in electronics,” the statement reads. “These could be fed into the industrial recycling and supply chains.”

The researchers acknowledge that there are likely to be issues of contamination with hazardous materials in some landfills set for excavation and mining. However, with appropriate safety measures in place during the process, landfill mining has great potential for the reuse of erstwhile waste and the possibility of remediating sites either for development or repurposing as wildlife reserves, or simply ensuring that they revert to their natural state.